Elements and compounds Flashcards
Properties of Metals
- Solids at room temperature (except mercury)
- High Melting and Boiling points
- Hard and dense
- Good conductors of electricity
- Good conductors of heat
- They are malleable and ductile
- They are grey in color (except gold and copper)
- Sonorous
Properties of Non-Metals
- Solids and gases at room temperature (except bromine)
- Often low Melting and boiling points
- Soft but diamond is very hard, low densities.
- Poor conductors of electricity, they are insulators, (Except graphite)
- Poor thermal conductors
- Brittle when solid
- Vary in colors, dull surfaces
- Not sonorous
Metals and Non-metals
- Metals are elements that conduct electricity and are malleable and ductile.
- Non-metals are elements that do not conduct electricity well and are neither malleable nor ductile
Metalloids
Looks like metals but brittle like nonmetal, they are neither conductors nor insulators.
Reactivity
Group 1 - Increase down the group
Group 7/17 - decreases down the group.
Density
Group 1 - Increases down the group
Group 7 - Decreases down the group
Melting points
Group 1 - Decreases down the group
Group 7 - Increases down the group.
Alkali metals
most reactive metals that occur. They are known as alkali metals because they react vigorously with water to
produce hydrogen and an alkaline solution.
Properties of halogens
- Poisonous and have a similar strong smell
- They are all non-metals
- They all form diatomic molecules
- They all have a valency
- Their compounds with hydrogen are usually strong acids when dissolved in water.
- They each produce a series of compounds with
other elements, known as halides - The halogens themselves can react directly with
metals to form metal halides (salts) - They all form negative ions carrying a single
charge
Noble gases
- The electron arrangements of the atoms of the noble gases are very stable.
- They do not react readily with other atoms.
Transition Metals (Properties)
- Hard and strong
- High density
- High melting and boiling points
- Many of their compounds are colored
- Show more than 1 valency, they form more than 1 ion.
Bonding in elements
- Metallic elements are held together by metallic bonding, which results in metallic lattices
- Covalent bonding or exist as separate atoms. Covalent bonding results in simple molecules or giant molecular lattices.
Ions
A charged particle made from an atom by the loss or gain of electrons.
Covalent bonding
- Formed by sharing 2 atoms.
- Each atom contributes 1 to each bound
- Molecules are formed from atoms linked together.
Bonding in compounds
- Non-metals plus non-metals compounds are held together by covalent bonding which results in simple molecules or giant molecular lattices.
- Metals plus non-metals compounds are held together by ionic bonding, which results in giant ionic lattices.
Ionic compound Features
- The electrons involved in the formation of ions are the outer shell electrons of atoms
- Metal ions lose their outer electron to be positive ions, they became more stable similar to the arrangement of the nearest noble gas
- Atoms of non-metal gain electrons to become negative ions they became more stable similar to the arrangement of the nearest noble gas
- The number of positive charges on a metal equal to the number of electrons lost
- ionic bonds result in the attraction of opposite charges.
- The number of negative charges on a metal equal to the number of electrons gained.
Properties of ionic bonding
- They are crystalline solids at room temp because there is a regular arrangement
- they have high melting and boiling points because ions are attracted to each other by strong electrostatic.
- They are soluble in water because water is attracted to charged ions and therefore many ionic solids dissolve
- They conduct electricity when molten or dissolved in water because the water molecules are free to move so they carry electric ions.
Simple covalent compounds
- They are often liquids or gases at room temperature because of these substances made of simple molecules.
- Low melting and boiling points because the intermolecular forces are very weak
- Soluble in organic solution
- They do not conduct electricity because there are no free ions.
Giant mettalic lattice
A lattice of positive ions in a sea of electrons
Giant ionic lattice
a lattice alternating positive and negative ions
Giant molecular lattice
A giant molecule making the lattice
Simple molecular substances
Consisting of simple molecules in a lattice held together by the weak force.
Rf formula
Distance moved by substance / Distance moved by the solvent front
Colors
FeCl2 - Grey Green
FeCl3 - Red Brown
